Is VAW on old VMware supported?

[ianbutton1]

We lost our VMware specialist some time ago, and our VMware infrastructure is old (ESXi/vSphere 5.1) and out of support, so we are migrating to HyperV - but a few VMs can't be migrated just yet. In the meantime, I want to upgrade our VBR to V10, but I understand that V10 does not support such an old version of vSphere. Does that mean that if I upgrade our VBR our VMware guest backups will fail, or just that support isn't guaranteed in case of a problem?
As a workaround, I wondered about installing VAW on these few VMs and using that to back them up instead of the VBR VMware job. A test installation has worked, though the Protection Group on the Inventory page shows the machine as "Unsupported OS". I haven't tested a backup yet (will it work?) - but is this scenario supported or not?
Some might say that if we're not worried about support for VMware itself, why worry about Veeam support - but I thought I would ask, in case anyone has tried this idea of VAW on an (old) VMware guest.
TIA

[Egor Yakovlev]

As long as Guest OS meets VAW System Requirements backup will work no matter of underlying virtualization platform.
/Cheers!